| An artist's reconstruction of the Hagerman Horse skeleton--Equus simplicidens, whose mineralized remains occur in the 3.5 to 3.0 million year-old section of Pliocene Coso Formation, Coso Mountains, California. Equus simplicidens is considered one of the earliest known members of the genus Equus, which includes the modern horse and all other equids. Named for its spectacular occurrences at Hagerman Fossil Beds National Monument in Idaho. Photograph courtesy Hagerman Valley Historical Society Museum. |